In the field of composite material repair, or rework, heat is often applied to a region of the composite material requiring repair, or rework. Structures, including, but not limited to stationary structures and objects, as well as vehicles, including, but not limited to aircraft are being designed and manufactured with increasing percentages of parts made from composite materials. Composite materials offer desired strength with less weight as compared to, for example, metal-containing parts. In the case of aircraft and other vehicles, the decreased weight afforded by the use of composite materials improves performance features including, for example, payload capacity and fuel efficiency. In addition, composite materials generally provide longer service life for various components on vehicles, including, for example, aircraft.
Composite materials are understood to be strong, light-weight materials created by combining two or more compositions. For example, composite materials often include reinforcing fibers bound in a polymer resin matrix. Resins used in composite materials may be thermoset or thermoplastic resins. A composite material made with a thermoplastic resin may become soft upon heating, may re-harden upon cooling, and may be able to be repeatedly heated and cooled.
During manufacturing of composite materials, such materials may have localized areas containing one or more inconsistencies or irregularities. Such inconsistencies or irregularities may undesirably influence properties of the components or parts made from the composite material. As a result, such areas of the parts made from composite material having such areas of inconsistencies or irregularities must be repaired or “reworked” to improve the properties and performance of the part as well as the overall structure comprising the part.
Repairs can be performed on composite materials using mechanical systems over inconsistencies with the mechanical systems secured using mechanical fasteners. However, the use of mechanical systems for composite material repair may not be possible for certain composite parts. In addition, the use of mechanical repair solutions can increase the stress concentration at the site of composite irregularities.
Localized heating in the form of, for example, hot bonded repair, of composite materials at the localized site or region of composite material irregularities has been used as a method for reworking some composite materials. However, the localized heating can damage or otherwise adversely impact composite and non-composite materials that adjoin or are otherwise proximate to the composite material being reworked.
Efforts have been made to maintain, regulate and otherwise control the temperature of structures that adjoin composite parts that are being reworked and subjected to heating. Such efforts have included applying conditioned air to the structures, applying chilled apparatuses such as, for example, shot bags containing chilled metal pellets, separating and insulating structures from the composite materials being reworked, etc. In some cases, it has been necessary to remove adjoining structures, parts and components that are thermally sensitive from their installed locations when reworking composite parts via heating. Such part removal and re-installation increases the risk of additional part damage during removal and re-installation, and is time-consuming, labor intensive, and costly.